src/code/thread.lisp

   1 ;;;; support for threads needed at cross-compile time
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!THREAD")
  13
  14 (def!type thread-name ()
  15   'simple-string)
  16
  17 (def!struct (thread (:constructor %make-thread))
  18   #!+sb-doc
  19   "Thread type. Do not rely on threads being structs as it may change
  20 in future versions."
  21   (name          nil :type (or thread-name null))
  22   (%alive-p      nil :type boolean)
  23   (os-thread     nil :type (or integer null))
  24   (interruptions nil :type list)
  25   (result        nil :type list)
  26   (interruptions-lock
  27    (make-mutex :name "thread interruptions lock")
  28    :type mutex)
  29   (result-lock
  30    (make-mutex :name "thread result lock")
  31    :type mutex)
  32   waiting-for)
  33
  34 (def!struct mutex
  35   #!+sb-doc
  36   "Mutex type."
  37   (name   nil :type (or null thread-name))
  38   (%owner nil :type (or null thread))
  39   #!+(and (not sb-lutex) sb-thread)
  40   (state    0 :type fixnum)
  41   #!+(and sb-lutex sb-thread)
  42   (lutex (make-lutex)))
  43
  44 (defun mutex-value (mutex)
  45   "Current owner of the mutex, NIL if the mutex is free. May return a
  46 stale value, use MUTEX-OWNER instead."
  47   (mutex-%owner mutex))
  48
  49 (defun holding-mutex-p (mutex)
  50   "Test whether the current thread is holding MUTEX."
  51   ;; This is about the only use for which a stale value of owner is
  52   ;; sufficient.
  53   (eq sb!thread:*current-thread* (mutex-%owner mutex)))
  54
  55 (defsetf mutex-value set-mutex-value)
  56
  57 (declaim (inline set-mutex-value))
  58 (defun set-mutex-value (mutex value)
  59   (declare (ignore mutex value))
  60   (error "~S is no longer supported." '(setf mutex-value)))
  61
  62 (define-compiler-macro set-mutex-value (&whole form mutex value)
  63   (declare (ignore mutex value))
  64   (warn "~S is no longer supported, and will signal an error at runtime."
  65         '(setf mutex-value))
  66   form)
  67
  68 (def!struct spinlock
  69   #!+sb-doc
  70   "Spinlock type."
  71   (name  nil :type (or null thread-name))
  72   (value nil))
  73
  74 (sb!xc:defmacro with-mutex ((mutex &key (value '*current-thread*) (wait-p t))
  75                             &body body)
  76   #!+sb-doc
  77   "Acquire MUTEX for the dynamic scope of BODY, setting it to VALUE or
  78 some suitable default value if NIL.  If WAIT-P is non-NIL and the mutex
  79 is in use, sleep until it is available"
  80   `(dx-flet ((with-mutex-thunk () ,@body))
  81      (call-with-mutex
  82       #'with-mutex-thunk
  83       ,mutex
  84       ,value
  85       ,wait-p)))
  86
  87 (sb!xc:defmacro with-system-mutex ((mutex
  88                                     &key without-gcing allow-with-interrupts)
  89                                    &body body)
  90   `(dx-flet ((with-system-mutex-thunk () ,@body))
  91      (,(cond (without-gcing
  92                'call-with-system-mutex/without-gcing)
  93              (allow-with-interrupts
  94               'call-with-system-mutex/allow-with-interrupts)
  95              (t
  96               'call-with-system-mutex))
  97        #'with-system-mutex-thunk
  98        ,mutex)))
  99
 100 (sb!xc:defmacro with-system-spinlock ((spinlock &key) &body body)
 101   `(dx-flet ((with-system-spinlock-thunk () ,@body))
 102      (call-with-system-spinlock
 103        #'with-system-spinlock-thunk
 104        ,spinlock)))
 105
 106 (sb!xc:defmacro with-recursive-lock ((mutex) &body body)
 107   #!+sb-doc
 108   "Acquires MUTEX for the dynamic scope of BODY. Within that scope
 109 further recursive lock attempts for the same mutex succeed. It is
 110 allowed to mix WITH-MUTEX and WITH-RECURSIVE-LOCK for the same mutex
 111 provided the default value is used for the mutex."
 112   `(dx-flet ((with-recursive-lock-thunk () ,@body))
 113      (call-with-recursive-lock
 114       #'with-recursive-lock-thunk
 115       ,mutex)))
 116
 117 (sb!xc:defmacro with-recursive-spinlock ((spinlock) &body body)
 118   `(dx-flet ((with-recursive-spinlock-thunk () ,@body))
 119      (call-with-recursive-spinlock
 120       #'with-recursive-spinlock-thunk
 121       ,spinlock)))
 122
 123 (sb!xc:defmacro with-recursive-system-spinlock ((spinlock
 124                                                  &key without-gcing)
 125                                                 &body body)
 126   `(dx-flet ((with-recursive-system-spinlock-thunk () ,@body))
 127      (,(cond (without-gcing
 128                'call-with-recursive-system-spinlock/without-gcing)
 129              (t
 130               'call-with-recursive-system-spinlock))
 131        #'with-recursive-system-spinlock-thunk
 132        ,spinlock)))
 133
 134 (sb!xc:defmacro with-spinlock ((spinlock) &body body)
 135   `(dx-flet ((with-spinlock-thunk () ,@body))
 136      (call-with-spinlock
 137       #'with-spinlock-thunk
 138       ,spinlock)))
 139
 140 (macrolet ((def (name &optional variant)
 141              `(defun ,(if variant (symbolicate name "/" variant) name)
 142                   (function mutex)
 143                 (declare (function function))
 144                 (flet ((%call-with-system-mutex ()
 145                          (dx-let (got-it)
 146                            (unwind-protect
 147                                 (when (setf got-it (get-mutex mutex))
 148                                   (funcall function))
 149                              (when got-it
 150                                (release-mutex mutex))))))
 151                   (declare (inline %call-with-system-mutex))
 152                   ,(ecase variant
 153                      (:without-gcing
 154                        `(without-gcing (%call-with-system-mutex)))
 155                      (:allow-with-interrupts
 156                        `(without-interrupts
 157                           (allow-with-interrupts (%call-with-system-mutex))))
 158                      ((nil)
 159                       `(without-interrupts (%call-with-system-mutex))))))))
 160   (def call-with-system-mutex)
 161   (def call-with-system-mutex :without-gcing)
 162   (def call-with-system-mutex :allow-with-interrupts))
 163
 164 #!-sb-thread
 165 (progn
 166   (macrolet ((def (name &optional variant)
 167                `(defun ,(if variant (symbolicate name "/" variant) name)
 168                     (function lock)
 169                   (declare (ignore lock) (function function))
 170                   ,(ecase variant
 171                     (:without-gcing
 172                       `(without-gcing (funcall function)))
 173                     (:allow-with-interrupts
 174                       `(without-interrupts
 175                          (allow-with-interrupts (funcall function))))
 176                     ((nil)
 177                       `(without-interrupts (funcall function)))))))
 178     (def call-with-system-spinlock)
 179     (def call-with-recursive-system-spinlock)
 180     (def call-with-recursive-system-spinlock :without-gcing))
 181
 182   (defun call-with-mutex (function mutex value waitp)
 183     (declare (ignore mutex value waitp)
 184              (function function))
 185     (funcall function))
 186
 187   (defun call-with-recursive-lock (function mutex)
 188     (declare (ignore mutex) (function function))
 189     (funcall function))
 190
 191   (defun call-with-spinlock (function spinlock)
 192     (declare (ignore spinlock) (function function))
 193     (funcall function))
 194
 195   (defun call-with-recursive-spinlock (function spinlock)
 196     (declare (ignore spinlock) (function function))
 197     (funcall function)))
 198
 199 #!+sb-thread
 200 ;;; KLUDGE: These need to use DX-LET, because the cleanup form that
 201 ;;; closes over GOT-IT causes a value-cell to be allocated for it --
 202 ;;; and we prefer that to go on the stack since it can.
 203 (progn
 204   (defun call-with-system-spinlock (function spinlock)
 205     (declare (function function))
 206     (without-interrupts
 207       (dx-let (got-it)
 208         (unwind-protect
 209              (when (setf got-it (get-spinlock spinlock))
 210                (funcall function))
 211           (when got-it
 212             (release-spinlock spinlock))))))
 213
 214   (macrolet ((def (name &optional variant)
 215                `(defun ,(if variant (symbolicate name "/" variant) name)
 216                     (function spinlock)
 217                   (declare (function function))
 218                   (flet ((%call-with-system-spinlock ()
 219                            (dx-let ((inner-lock-p
 220                                      (eq *current-thread*
 221                                          (spinlock-value spinlock)))
 222                                     (got-it nil))
 223                              (unwind-protect
 224                                   (when (or inner-lock-p
 225                                             (setf got-it
 226                                                   (get-spinlock spinlock)))
 227                                     (funcall function))
 228                                (when got-it
 229                                  (release-spinlock spinlock))))))
 230                     (declare (inline %call-with-system-spinlock))
 231                     ,(ecase variant
 232                       (:without-gcing
 233                         `(without-gcing (%call-with-system-spinlock)))
 234                       ((nil)
 235                         `(without-interrupts (%call-with-system-spinlock))))))))
 236     (def call-with-recursive-system-spinlock)
 237     (def call-with-recursive-system-spinlock :without-gcing))
 238
 239   (defun call-with-spinlock (function spinlock)
 240     (declare (function function))
 241     (dx-let ((got-it nil))
 242       (without-interrupts
 243         (unwind-protect
 244              (when (setf got-it (allow-with-interrupts
 245                                  (get-spinlock spinlock)))
 246                (with-local-interrupts (funcall function)))
 247           (when got-it
 248             (release-spinlock spinlock))))))
 249
 250   (defun call-with-mutex (function mutex value waitp)
 251     (declare (function function))
 252     (dx-let ((got-it nil))
 253       (without-interrupts
 254         (unwind-protect
 255              (when (setq got-it (allow-with-interrupts
 256                                  (get-mutex mutex value waitp)))
 257                (with-local-interrupts (funcall function)))
 258           (when got-it
 259             (release-mutex mutex))))))
 260
 261   (defun call-with-recursive-lock (function mutex)
 262     (declare (function function))
 263     (dx-let ((inner-lock-p (eq (mutex-%owner mutex) *current-thread*))
 264              (got-it nil))
 265       (without-interrupts
 266         (unwind-protect
 267              (when (or inner-lock-p (setf got-it (allow-with-interrupts
 268                                                   (get-mutex mutex))))
 269                (with-local-interrupts (funcall function)))
 270           (when got-it
 271             (release-mutex mutex))))))
 272
 273   (defun call-with-recursive-spinlock (function spinlock)
 274     (declare (function function))
 275     (dx-let ((inner-lock-p (eq (spinlock-value spinlock) *current-thread*))
 276           (got-it nil))
 277       (without-interrupts
 278         (unwind-protect
 279              (when (or inner-lock-p (setf got-it (allow-with-interrupts
 280                                                   (get-spinlock spinlock))))
 281                (with-local-interrupts (funcall function)))
 282           (when got-it
 283             (release-spinlock spinlock)))))))